I am Catholic and can testify that this novena is one of the most powerful for women trying to conceive. It is a 9-day novena, which I highly recommend:

Novena to Saint Gerard

Strive each day to practice in the virtue indicated in the petition.

1st Day
Saint Gerard, ever full of faith obtain for me that , believing firmly all that the Church of God proposes to my belief, I may strive to secure through a holy life the joys of eternal happiness.

Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

Let us Pray

O Almighty and everlasting God, who didst draw to thyself Saint Gerard, even from his tenderest years, making him conformable to the Image of Thy Crucified Son, grant we beseech Thee, that imitating his example, through Jesus Christ our Lord. Amen.

2nd Day
Saint Gerard, most generous saint, who from thy tenderest years didst care so little for the goods of earth, grant that I may place all my confidence in Jesus Christ alone, my true Treasure, who alone can make me happy in time and in eternity.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

3rd Day
Saint Gerard, bright seraph of love, who despising all earthly love, didst consecrate thy life to the service of God and thy neighbor, promoting Godâs glory in thy lowly state, and ever ready to assist the distressed and console the sorrowful, ob5tain for me, I beseech thee, that loving God the only God and my neighbor for His sake, I may be hereafter united to Him for ever in glory.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

4th Day
Saint Gerard, spotless lily of purity, by the angelic virtue and thy wonderful innocence of life thou didst receive from the Infant Jesus and His Immaculate Mother, sweet pledges of tenderest love, grant, I beseech thee, that I may ever strive in my life-long fight, and thus win the crown that awaits the brave and the true.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

5th Day
Saint Gerard, model of holy obedience, who through thy life didst heroically submit the judgment to those who represent Jesus Christ to thee, thus sanctifying thy lowliest actions, obtain for me from God cheerful admission to His Holy Will and the virtue of perfect obedience, that I may be made comfortable to Jesus, my Model, who was obedient even to death.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

6th Day
Saint Gerard, most perfect imitator of Jesus Christ our Redeemer, do thou whose greatest glory was to be humble and lowly, obtain that I too, knowing my littleness in Godâs sight, may be found worthy to enter the kingdom that is promised to the humble and lowly of heart.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

7th Day
Saint Gerard, unconquered hero, most patient in suffering, do thou who didst glory in infirmity, and under slander and most cruel ignominy didst rejoice to suffer with Christ, obtain for me patience and resignation in my sorrows, that I may bravely bear the cross that is to gain for me the crown of everlasting glory.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

8th Day
Saint Gerard, true lover of Jesus in the Blessed Sacrament of the Altar, do thou who didst kneel long hours before the Tabernacle, and there didst taste the joys of the Paradise. Obtain for me, I beseech thee, the spirit of prayer and an undying love for the Most Holy Sacrament, that thus receiving frequently the Body and Blood of Jesus, I may daily grow in His holy love and merit the priceless grace of loving Him even to the end.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.

9th Day
Saint Gerard, most favorite child of heaven, to whom Mary gave the Infant Jesus in the day of thy childhood, to whom she sweetly came before thou didst close thine eyes In death, obtain for me I beseech thee, so to seek and love my Blessed Mother during life, that she may be my joy and consolation in this valley of tears, until with thee, before the throne of God, I may praise her goodness for all eternity. Amen.
Then say Nine Hail Marys, with the following Versicle and Prayer.
V. Pray for us, O Saint Gerard.
R. That we may be made worthy of the promises of Christ.